In high-temperature, high-pressure, and high sulfur gas wells, corrosion inhibitor prefilm technology, as an economic method, is a commonly used for controlling corrosion of downhole tubing. The fluid inside the tubing has characteristics of multiphase turbulent flow, which affects the adsorption efficiency of corrosion inhibitors. Therefore, it is of significance to study the film-forming characteristics of corrosion inhibitors under flow conditions. In this paper, Based on Re-Normalization Group (RNG) k-ε model, Euler Wall Film (EWF) model and multiphase flow theory, the prefilm process of two different corrosion inhibitors under flow conditions in high-temperature, high-pressure, and high sulfur gas wells were simulated using Fluent software. The adhesion law of corrosion inhibitors on the tubing wall and the scouring effect of gas flow on corrosion inhibitor liquid film after gas injection stoppage were invest gated. And the stability of two different corrosion inhibitors on tubing wall were compared. The research results show that compared to CT12-19C corrosion inhibitor, The CT12-19 corrosion inhibitor with higher viscosity has a slower pre film speed in the same length of tubing. And the CT12-19 corrosion inhibitor maintains a more stable pre film thickness and distribution on tubing wall, which indicates its smaller gas scouring effect. The CT12-19 corrosion inhibitor forms a liquid film with a thickness of approximately 2.5 mm on the wall of the tubing wall. The prefilm Simulation evaluation of corrosion inhibitor provides theoretical reference for optimizing the corrosion inhibitor, determining pre-film cycle and controlling the pre-filming quality of the corrosion inhibitor.